Case ce-0183-japanese-ime-space-conversion-chrome · Scenario scenario-space-during-composition

Japanese IME Space key conflicts with kanji conversion

OS: Windows 11 Device: Desktop or Laptop Any Browser: Chrome 120.0 Keyboard: Japanese (IME) Status: draft
composition ime space japanese chrome windows

Phenomenon

When using Japanese IME in a contenteditable element, the Space key is used for kanji conversion, which conflicts with inserting a space character. Pressing Space during composition may trigger conversion instead of inserting a space, or may behave inconsistently compared to native text controls.

Reproduction example

  1. Focus the editable area.
  2. Activate Japanese IME.
  3. Type romaji text (e.g., “kanji”).
  4. Press Space to trigger kanji conversion.
  5. Try to insert a space character after conversion.

Observed behavior

  • Space key triggers kanji conversion instead of inserting a space character
  • After conversion, inserting a space may require multiple Space presses
  • Behavior may differ from native text input controls
  • The order of events (composition, conversion, space insertion) may be inconsistent

Expected behavior

  • Space key behavior should be consistent across contenteditable and native text inputs
  • Users should be able to reliably insert space characters
  • Conversion and space insertion should not conflict

Browser Comparison

  • Chrome: Space key behavior may conflict with conversion
  • Edge: Similar to Chrome
  • Firefox: May have different behavior
  • Safari: Not applicable on Windows

Notes and possible direction for workarounds

  • Monitor composition and conversion state to distinguish between conversion Space and insertion Space
  • Consider using alternative methods to insert spaces during composition
  • Handle Space key events carefully during active composition
Before
Hello かんじ
Japanese romaji input in progress (kanji → かんじ)
After Space (Bug)
Hello 漢字
Space key converts to kanji, space insertion fails
vs
✅ Expected
Hello 漢字
Expected: Space inserted after kanji conversion

Browser compatibility matrix

This matrix shows which browser and OS combinations have documented cases for this scenario. The current case is highlighted. Click on a cell to view other cases.

Current case
Confirmed
Draft
No case documented

All variants (detailed table)

Complete list of all cases for this scenario with full environment details.

Case OS Device Browser Keyboard Status
ce-0010-space-lost-during-composition Windows 11 Desktop or Laptop Any Edge 120.0 Korean (IME) draft
ce-0183-japanese-ime-space-conversion-chrome Windows 11 Desktop or Laptop Any Chrome 120.0 Japanese (IME) draft
ce-0184-thai-ime-space-ignored-firefox Windows 11 Desktop or Laptop Any Firefox 120.0 Thai (IME) draft
ce-0197-arabic-ime-space-ignored-chrome Windows 11 Desktop or Laptop Any Chrome 120.0 Arabic (IME) draft
ce-0198-hindi-ime-space-ignored-firefox Windows 11 Desktop or Laptop Any Firefox 120.0 Hindi (IME - Devanagari) draft

Playground for this case

Use the reported environment as a reference and record what happens in your environment while interacting with the editable area.

Reported environment
OS: Windows 11
Device: Desktop or Laptop Any
Browser: Chrome 120.0
Keyboard: Japanese (IME)
Your environment
Sample HTML:
Event log
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0 events
Interact with the editable area to see events here.

Comments & Discussion

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